Fresh water is an increasingly scarce and expensive natural resource necessary to sustain life. The availability of potable or fresh water frequently is the factor which limits growth of a locality, or even growth within a locality. Not only is the treatment of potable water for consumption expensive, but treatment of the resulting waste water is also of increasing expense on account of treatment and capital costs.
Many modern large facilities, such as office buildings, hotels, stadia and the like, have a demand load for potable water which varies substantially from day to day, and even hour to hour. For example, the demand for potable water during an intermission at a stadium greatly exceeds the demand while the event is underway. Similarly, the demand for potable water on a given floor of a hotel or office building may greatly exceed the demand on other floors.
The ability to expand an existing facility, such as a hospital, is frequently limited by the availability of potable water. Furthermore, the cost of expansion is also related to the water main size which must be provided, and most localities charge access fees of one type or another based upon the meter size required to supply the facility. Frequently, expansion may only occur if the existing water main is removed and replaced by a larger one. In some instances, such as in a hospital, it is not possible to totally deprive the facility of water, thereby prohibiting expansion if the existing water supply is not sufficient.
Current design techniques utilize various factors and extrapolations for estimating the potable water demand of a given facility. Once the demand has been determined, then line size, meter size, main size and the like can be developed based upon this estimated demand. Unfortunately, such estimates are quite crude and do not take into account the wide swings in demand which occur. Furthermore, the resulting line size is generally based upon some percentage of the line size required for total estimated demand because it is accepted that total demand will only infrequently occur. The result of this is, however, that tremendous fluctuations in pressure and flow occur in response to demand, particularly as demand exceeds the percentage factor and approaches 100% demand.
A further complicating factor in sizing water lines is due to the infrequent requirements of the fire and/or water department. For example, utilization of an hydrant will have a tremendous effect on pressure in the main, thereby requiring the water department to place more pumps on line in order to keep pressure constant, or else run the risk of the water main pressure dropping by too great an amount. Similarly, a broken water main in one location can have an effect on main pressure in another location.
The disclosed invention is a fresh water distribution control system and method which utilizes a plurality of sensors and electromagnetically operated valves in order to precisely control water supply in response to demand. The system and method make maximum utility of the existing water supply in order to smooth out the pressure and flow fluctuations which occur as demand fluctuates. The system and method furthermore permit the supply to be adjusted in response to external and internal factors.